The present disclosure provides a mask and a fabricating method thereof, and a displaying base plate and a fabricating method thereof, and relates to the technical field of displaying. The mask includes a mask part and a peripheral part surrounding the mask part; the mask part includes at least one mask unit, and the mask unit includes an opening and a first main body surrounding the opening; and a thickness of at least part of area of the peripheral part is greater than a thickness of the mask part, and the peripheral part is configured to contact a base plate to be formed with a film, and support the base plate to be formed with a film, whereby the mask part and the base plate to be formed with a film have a gap therebetween.